The topic of this diploma thesis is the usage of marijuana in therapeutical purposes and reasons pro and contra of using marijuana and preparations based on marijuana as medicines. The usage of medical marijuana is allowed in several economically and technologically developed countries. Still, there is a big number of other countries that consider marijuana as dangerous „drug“, which casts a shadow on marijuana’s therapeutical potential. This diploma thesis shows marijuana through history, from time of use in ancient medicine to banned substances, which in most states is in the first category of drugs. Putting marijuana in that category states that she has high abuse potential and no proven therapeutic effect. On the other side, the number of people who suffer from different sorts of diseases are claiming that marijuana had helped them, taken in combination with other drugs or alone, when conventional therapy had weak effect or had serious adverse effects. Through large number of studies and individual experiences of sick people, we tried to remove stereotypes that were linked to marijuana over years. Developed countries are investing a lot in medical marijuana research, which makes the possibility that marijuana will enter out pharmaceutical market and pharmacies even bigger. The goal of our questionnaire which was taken among pharmacist in Croatia was to find out what is their attitude about therapeutic usage of marijuana. We also wanted to find out how much pharmacists are educated about benefits and adverse effects of this kind of medical treatment.